From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20111207165602.002157755@clark.kroah.org> Date: Wed, 07 Dec 2011 08:54:52 -0800 From: Greg KH To: , Cc: , , , Jiri Slaby , James Bottomley Subject: [19/27] SCSI: scsi_lib: fix potential NULL dereference In-Reply-To: <20111207165611.GA19872@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Slaby commit 03b147083a2f9a2a3fbbd2505fa88ffa3c6ab194 upstream. Stanse found a potential NULL dereference in scsi_kill_request. Instead of triggering BUG() in 'if (unlikely(cmd == NULL))' branch, the kernel will Oops earlier on cmd dereference. Move the dereferences after the if. Signed-off-by: Jiri Slaby Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/scsi_lib.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1370,9 +1370,9 @@ static int scsi_lld_busy(struct request_ static void scsi_kill_request(struct request *req, struct request_queue *q) { struct scsi_cmnd *cmd = req->special; - struct scsi_device *sdev = cmd->device; - struct scsi_target *starget = scsi_target(sdev); - struct Scsi_Host *shost = sdev->host; + struct scsi_device *sdev; + struct scsi_target *starget; + struct Scsi_Host *shost; blk_start_request(req); @@ -1382,6 +1382,9 @@ static void scsi_kill_request(struct req BUG(); } + sdev = cmd->device; + starget = scsi_target(sdev); + shost = sdev->host; scsi_init_cmd_errh(cmd); cmd->result = DID_NO_CONNECT << 16; atomic_inc(&cmd->device->iorequest_cnt);